Study On Binocular Stereo Imaging Based On Computer Stereo Vision

Binocular stereo imaging means capturing, producing and transmitting a scene, and then displaying it with stereoscopic perception based on the basic principles of binocular stereo vision. Binocular stereo imaging based on computer stereo vision is not only the key technique to realize the stereoscopic display of the virtual plant, but also widely used in many fields such as virtual reality, machine vision, multimedia education, digital entertainment, appearance design of industrial products, sculpture and architecture etc. The purpose of this dissertation is to probe into binocular stereo imaging based on computer stereo vision, which will provide the theories and techniques support for its applications.In this dissertation, the theories and techniques related to binocular stereo imaging based on computer stereo vision are firstly studied. Based on this foundational work, a binocular stereo imaging model based on monitor is proposed and the properties of this model are thoroughly discussed. Finally, with the help of the model and subsequent experiments, three kinds of methods for acquiring stereo pair for the model combined with experiments are elaborated: stereo pair creation based on Hou method, stereo pair creation when 3D models are given, and stereo pair creation based on monocular video frequency image sequence.The main research results of this dissertation are summarized as follows.With respect to occlusion, the dissertation argued that, the theory of qualitative representation and reasoning of spatial relations can be used for the representation of the positional relations among objects in computer and the comprehension of this kind of relations by computer. As for qualitative representation of spatial relations, a SR representation model is presented and further provided is the qualitative representation models of distance and directional relations. As for qualitative reasoning of spatial relations, the composition operation is defined based on SR representation model and the corresponding composition operation table is also presented. Furthermore, we create qualitative subtraction table of distance, qualitative subtraction table of angle and the QTR composition operation table which is needed for qualitative trigonometry reasoning. Compared with the quantitative method, the qualitative method can considerably reduce the time complexity and space complexity. As for imaging model, the dissertation introduces a binocular stereo imaging model based on monitor. Then it focuses on the imaging properties of the model. The formula for computing the coordinates of stereo pairs is given; the parallax and its properties are discussed; we also present the rules of stereo imaging of point and line segment, and experiments have been carried out to prove the conclusions. Theoretical analysis and the experimental results show that, the observer can see the image still move when his eyes move away from or towards the screen when the depth of each point of the image is the same, and the image won't be distorted; on the other hand, if the depth of each point of the image is different, the image will be distorted by following certain imaging rules. The stereo images are measurable in the case of negative disparity.The dissertation presents two quantitative criterions, cross-entropy and root-mean-square error, to evaluate the stereo effect for Hou method. Besides, an algorithm named ProduceKmn, which is used to produce random numbers that accord with the requirement, is also presented. Moreover, we constructed six kinds of distributions for Hou method, such as Moving Pixels without Stretch, Uniform Distribution, Triangular distribution, Piecewise Uniform Distribution, Fitting Gray Value Distribution, and Normal Distribution. Meanwhile, on the basis of experiments, the impacts that the above-mentioned six distributions may have upon stereo effect have been discussed. In addition, the interrelation between the stereo effect and the number of sub-blocks has been also studied. The experimental results and the analysis show that, a) smoothness is incompatible with stereoscopic perception; b) Generally, the stereo effect is preferable when random variables have normal distribution; c) In contrast with other methods, Hou method is simple, and the stereoscopic perception is distinct, but its application scope is limited.The dissertation introduces a stereo pair creation method when 3D models are given. Meanwhile detailed discussion is focused on the important factors that exert great influence on stereo effect, such as positional relations between the target cameras and the 3D Model, length of the baseline, position of the virtual image and imaging distortion, etc. Moreover, corresponding rules of imaging are also presented.Last but not least, the dissertation also touches on the influence that parallax has upon depth perception, object extraction, time sequence & frame interval, etc. Accordingly, we presented a method to convert a monocular video frequency image sequence to a stereo one. Experiments have been carried out to test it. The results reveal that, better stereo effect will be perceived from the stereo video converted by this method when the camera or the objects in the scene make horizontal movements or approximately horizontal movements.